INTERVENTION SUMMARY. Currently available. Post-slaughter carcasse or packaging. Surface treatment of carcase, primals, offal

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1 Organic Acids INTERVENTION SUMMARY Status Location Intervention type Treatment time Regulations Effectiveness Likely cost Value for money Plant or process changes Environmental impact OH&S Advantages Disadvantages or limitations Currently available Post-slaughter carcasse or packaging Surface treatment of carcase, primals, offal seconds depending on solution temperature Approved in US, Australia and some approved in EU 1-3 log reduction Could cost in the $100,000 to $300,000 range to install a cabinet If there is an existing wash cabinet, capital cost is low and may be good value estimated cost of solution $1.70 per beef carcass Spray cabinet will be required Disposal of chemicals may be an issue Acids are irritants, so careful handling is required Risk of inhalation of irritant Secure storage of the concentrate will be required Applied by spray or immersion Can be used with other treatment/technologies Much literature on efficacy Possible prolonged inhibition of microbial growth When applying by spray, the airborne aerosols - particularly of acetic acid - can have a corrosive effect on equipment surrounding the spray cabinet Concerns about acid-resistant microorganisms Page 1 of 6

2 Disclaimer Care is taken to ensure the accuracy of the information contained in this publication. However MLA cannot accept responsibility for the accuracy or completeness of the information or opinions contained in the publication. You should make your own enquiries before making decisions concerning your interests. Organic Acids Solutions of organic acids (1-3%), such as lactic and acetic acids, are the most frequently used chemical interventions in commercial plants for both beef and lamb dressing. Many other organic acids, however, have been researched either separately or as a mixture for use in chemical washes, including formic, propionic, citric, fumaric, and L-ascorbic acid. The mechanism of action of organic acids on the microbial cell is not completely understood, but it is hypothesised that it is the undissociated molecule of the acid that is responsible for the antimicrobial activity. In the US, organic acids are applied as part of a carcass wash pre-chill and can be applied at levels up to 2.5% (USDA/FSIS, 2004). In addition, lactic acid is approved for use on beef carcasses, sub-primals and trimmings (i.e. pre- and post-chill), offal and variety meats at levels up to 5% at temperatures not exceeding 55 C. The EU authorised the use of lactic acid for decontamination of bovine carcases from February 2013, based on a European Food Safety Authority (EFSA) opinion in 2011 (EFSA, 2011), whereas the USDA has specifically approved lactic acid, acetic acid, and citric acid as antimicrobial agents in the final wash that is applied to livestock carcases after trimming and inspection but before chilling (21 CFR (a) (3): FDA, 2003). There is a lot of variability in the literature in terms of the cited reductions that can be achieved. This is mainly due to differences in the concentrations and types of acids used by different researchers, the method of application, the types of samples tested, and the initial microbial load of samples. Organic acids have been shown to be most effective when applied as a warm (50-55 C) carcass rinse (Acuff, 2005). Unfortunately, the corrosive effect on the equipment seems to increase as the temperature rises. There are conflicting reports as to whether there is greater bacterial inhibition by acetic compared to lactic or citric acid washes. Lactic acid (2%) was shown to reduce E. coli O157:H7 on inoculated beef carcase tissue by 3.3 log units, and 2% acetic acid reduced it by 1.6 log units (Ransom et al., 2003). These authors also found that lactic acid and acetic acid treatments on cheekmeat, using spray or immersion, resulted in 1.1 log reductions in total bacteria. The lesser reductions were attributed to the physical structure of cheekmeat, which may protect microbes from the treatments. Organic acids (lactic, acetic, and propionic) have been reported to decrease populations of E. coli and other bacteria when sprayed on sheep/goat carcasses or used as a wash (Dubal et al., 2004; Ramirez et al., 2001). Laury et al. (2009) reported a reduction in E. coli O157:H7 of 1.4 log cfu/100 cm 2 on beef trim after spraying with a commercial lactic and citric acid-based antimicrobial product. Lactic acid was found to be more effective than acetic acid in reducing E. coli and Salmonella on inoculated samples of beef flank tissue (Arthur et al., 2008). Recent work by Carranza et al. (2013) found that an acetic acid spray treatment following water washing was Page 2 of 6

3 effective at reducing microbial load on beef carcases at a commercial Mexican slaughter house. They reported 0.8-log, 1.54-log and 1.4-log reductions in total plate count, total coliform and faecal coliform counts respectively, when carcasses were sprayed with a 2% acetic acid solution at psi for 60 seconds. In contrast, Gill (2009) concluded that, when looking at the results from three meat processing plants in the US, the apparent effects of the lactic acid spray could be attributed to the washing effect of the treatment rather than any antimicrobial effect of the lactic acid. Greig et al. (2012) performed a systematic review-meta-analysis of the published research, looking only at studies that reflected commercial processing conditions. They suggest that whilst the literature does show a greater decrease in the concentration and prevalence of generic E. coli, when an acid rinse is incorporated prior to dry chill, compared to dry chill alone, this increased efficacy is relatively small and needs to be evaluated against the increased cost of infrastructure and chemicals. There is some evidence that organic acids may enhance the shelf life of modified atmosphere packaged product, perhaps because they increase the lag phase of the microorganisms (Podolak et al., 1996). Carpenter et al. (2011) claimed that acid washing with acetic acid inhibited the growth of residual E. coli O157:H7 for about 2 days, on inoculated beef plate. However, detrimental sensory changes have been reported when beef sub-primals are treated with lactic acid (Smulders and Greer, 1998). Hot carcass surfaces treated with organic acids often display some discoloration of tissue or fat surfaces. However, as with hot water pasteurisation, this often disappears or becomes less evident after chilling. In the literature, there is also mention of the possibility for the use of organic acids to alter the microbial ecology of meat plant environments and consequently that of the beef (Acuff, 2005). However, there are concerns associated with using organic acids in that they may select for acidresistant bacteria that may accelerate rates of product spoilage, increase undesirable effects on product appearance and speed equipment corrosion (Gill, 1998; Stopforth et al., 2007). Page 3 of 6

4 Approximate costs for organic acid spray in beef/pork processing plants (A$, adapted from Reynolds, 2005) Organic acid List price (25kg Bangicid 88 Excel from IMCD Australia) Lactic Acid (88% food grade) 2% solution = 23 g + 1 litre H 2 O Cost per unit (ml) Cost per litre of solution Cost per carcass* $ (pig) 25.6 (beef) * Eight litres of 2% lactic acid will treat approximately 10 pigs or 5 beef carcasses. Proponent/Supplier Information Wash cabinets may be installed by a number of companies such as CHAD: CHAD Company West 161 st Street Olathe, KS United States Ph: Fax: Website: There are many food-grade acid suppliers in Australia. One larger company is IMCD Australia. IMCD Australia 1 st Floor, 372 Wellington Rd Mulgrave, VIC Ph: Fax Website: Page 4 of 6

5 References Acuff, G. R. (2005) Chemical decontamination strategies for meat. In: Improving the Safety of Fresh Meat (Ed: Sofos, J. N.) Woodhead Publishing Limited. CRC Press, New York. Pp Arthur, T.M., Kalchayanand, N., Bosilevac, J.M., Brichta-Harhay, D.M., Shackelford, S.D., Bono, J.L., Wheeler, T.L., Koohmaraie, M. (2008) Comparison of effects of antimicrobial interventions on multidrug-resistant Salmonella, susceptible Salmonella, and Escherichia coli O157:H7. Journal of Food Protection 71: Carpenter, C. E., Smith, J. V., Broadbent, J. R. (2011) Efficacy of washing meat surfaces with 2% levulinic, acetic, or lactic acid for pathogen decontamination and residual growth inhibition. Meat Science, 88(2): Carranza, L. R., Lozano, M. S. R., Medina, R. D. M., Rodarte, M. C. W., Espinosa, J. F. N., Camacho, B. L. V., Macedo, R. E. F. (2013) Acetic acid as an intervention strategy to decontaminate beef carcasses in Mexican commercial slaughterhouse. Food Science and Technology 33(3): Dubal, Z. B., Paturkar, A. M., Waskar, V. S., Zende, R. J., Latha, C., Rawool, D. B. Kadam, M. M. (2004) Effect of food grade organic acids on inoculated S. aureus, L. monocytogenes, E. coli and S. Typhimurium in sheep/goat meat stored at refrigeration temperature. Meat Science 66: EFSA Panel on Biological Hazards (BIOHAZ) (2011) Scientific Opinion on the evaluation of the safety and efficacy of lactic acid for the removal of microbial surface contamination of beef carcasses, cuts and trimmings. EFSA Journal 9: FDA (2003) Code of Federal Regulations Title 21, Government Printing Office, USA Gill, C. O. (1998) Microbiological contamination of meat during slaughter and butchering of cattle, sheep and pigs. In: The Microbiology of Meat and Poultry (Ed: Davies, A. and Board, R.) Blackie Academic & Professional, London. Pp Gill, C. O. (2009) Effects on the microbiological condition of product of decontaminating treatments routinely applied to carcasses at beef packing plants. Journal of Food Protection 72: Greig, J. D., Waddell, L., Wilhelm, B., Wilkins, W., Bucher, O., Parker, S., Rajic, A. (2012) The efficacy of interventions applied during primary processing on contamination of beef carcasses with Escherichia coli: A systematic review-meta analysis of the published research. Food Control, 27: Laury, A.M., Alvarado, M.V., Nace, G., Alvarado, C.Z., Brooks, J.C., Echeverry, A., Brashears, M.M. (2009) Validation of a lactic acid- and citric acid-based antimicrobial product for the reduction of Escherichia coli O157:H7 and Salmonella on beef tips and whole chicken carcasses. Journal of Food Protection 72: Podolak, R. K., Zayas, J. F., Kastner, C. L., Fung, D. Y. C. (1996) Reduction of bacterial populations on vacuum-packaged ground beef patties with fumaric and lactic acids. Journal of Food Protection. 59: Ramirez, A. J., Acuff, G. R., Lucia, L. M., Savell, J. W. (2001) Lactic acid and trisodium phosphate treatment of lamb breast to reduce bacterial contamination. Journal of Food Protection 64: Ransom, J. R., Belk, K. E., Sofos, J. N., Stopforth, J. D. Scanga, J. A., Smith, G. C. (2003) Comparison of intervention technologies for reducing Escherichia coli O157:H7 on beef cuts and trimmings. Food Protection Trends 23: Page 5 of 6

6 Reynolds, A. E. (2005) Utilisation of spray wash with organic acids (peroxyacetic acid and lactic acid) and chlorinated wash in combination, utilizing direct application methods, for pathogen reduction on pork and beef carcasses in small and very small meat processing plants. Research Note: FSIS New Food Safety Technologies Applicable for Small and Very Small Plants. Smulders, F. J. M., Greer, G. G. (1998) Integrating microbial decontamination with organic acids in HACCP programmes for muscle foods: prospects and controversies. International Journal of Food Microbiology, 44: Stopforth, J.D., Skandamis, P.N., Geornaras, I., Sofos, J.N. (2007) Acid tolerance of acid-adapted and nonacid-adapted Escherichia coli O157:H7 strains in beef decontamination runoff fluids or on beef tissue. Food Microbiology 24: USDA/FSIS (2004), Safe and suitable ingredients used in the production of meat and poultry products. FSIS Directive Amendment 6, USDA-FSIS. Page 6 of 6